This invention generally relates to a method of operating a receiver/transmitter that sends and receives signals to a remote transmitter.
A remote keyless entry system includes a receiver/transmitter disposed within a vehicle that communicates with a remote transmitter such as for example a key fob or other remote signaling device. The receiver sends out a Low Frequency (LF) signal to the remote actuation device, and the remote transmitter answers the receiver/transmitter by transmitting a radio frequency (RF) signal in recognition of the LF signal sent by the receiver/transmitter. Typically, the remote transmitter utilizes an Amplitude Shift Keyed (ASK) modulated RF signal for transmitting information to the receiver. The signal includes information utilized by the receiver/transmitter and system controller to initiate actuation of door locks, or other remotely controlled devices such as a remotely operated trunk, hatch or sliding door. A received signal strength indicator (RSSI) measures and decodes the incoming ASK modulated signal.
Disadvantageously, interference from surrounding RF signals such as for example garage door openers can overload the RSSI and prevent the desired ASK signal from being cleanly received resulting in difficulties remotely operating functions of the vehicle.
Accordingly, there is a need to develop a method of preventing unwanted signals from disrupting and preventing accurate and reliable communication between a receiver/transmitter and a remote actuation device.